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Gulkis, S.

Publications and source records attributed to Gulkis, S..

172 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

A note on the Gledhill model of the magnetosphere of Jupiter

Free-free emission from a constant density, isothermal rectangular of thickness 2 Jupiter radii and side dimensions 2 x 8 radii is considered. It is determined that the free-free emission from the Gledhill model exceeds the flux measured from the planet over the entire microwave spectrum. Consequently the electron density must be considerably less than Gledhill assumed (10 to the 9th power electrons/cu cm). The upper limit to the electron density which can be set by comparing free-free emission with the observed spectrum is approximately 10 to the 7th power electrons/cu cm.

Gulkis, S.↗
NASA NTRS1972

Thermal radio emission from Jupiter and Saturn

Microwave brightness temperature calculations have been carried out for a number of model atmospheres for Jupiter and Saturn. The models considered are characterized by helium to hydrogen number mixing ratios which range from 0 to 0.2. Gaseous ammonia is assumed to be a trace constituent in all the models. The ammonia abundance below the (NH3) cloud level is a free parameter which is determined by comparing the observed thermal spectrum of Jupiter and the total spectrum of Saturn with the model calculations. The theoretical microwave spectra corresponding to those models in which the ammonia abundance is that expected from an atmosphere containing a solar abundance of elements are found to be in generally good agreement with the observations. This result is shown to be nearly independent of the helium to hydrogen ratio for the models considered. There is no evidence at this time that a non-thermal component contributes to Saturn's microwave spectrum.

Gulkis, S.↗